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Abstract:

A mobile frame, for instance for moving less able-bodied persons,
comprising a castor with a wheel drive and pivot drive and operating
means for operating the wheel drive and the pivot drive for moving the
frame, wherein the operating means comprise a handle connected to the
bearing structure, a force detection assembly provided on the handles
and/or on the bearing frame, and which is configured for producing
signals which contain information about both the size of force and the
direction of force exerted on the handle, a control which is configured
for energizing the pivot drive for controlling the rotational position of
drive wheel support about the pivot depending on the direction of force,
and wherein the control is configured for energizing the wheel drive
depending on the size of force exerted on the handle.

Claims:

1. A mobile frame for moving less ablebodied persons, comprising:at least
one base bearing structure;at least one drive wheel which is rotatable
about a wheel central axis;at least one wheel drive configured for
driving the drive wheel about the wheel central axis;at least one drive
wheel support which is connected to the bearing structure in a manner
pivotable about a pivot and with which the drive wheel is connected for
rotation about the wheel central axis;a pivot drive configured for
pivoting the wheel support about the pivot with respect to the bearing
structure; andan operating device that operates the wheel drive and the
pivot drive for moving the frame, the operating device comprising:a
handle connected to the bearing structure;a force detection assembly
provided on the handle and/or on the bearing structure, and configured
for producing signals containing information about both the size of the
force and the direction of force which is exerted on the handle; anda
control, of which an input is connected to the force detection assembly,
and of which a first output is connected to the at least one wheel drive
and of which a second output is connected to the at least one pivot
drive, the control being configured for energizing the pivot drive for
controlling the rotational position of drive wheel support about the
pivot depending on the direction of force, and wherein the control is
configured for energizing the wheel drive depending on the size of force
exerted on the handle.

2. The frame according to claim 1, wherein the handle is non-movably
connected to the bearing structure.

3. The frame according to claim 1, wherein the force detection assembly is
configured for measuring an elastic deformation of the operating handle
and/or the bearing frame, which occurs under the influence of a force
exerted by a user on the handle and for converting this measured
deformation into signals which contain information about both the size of
the force and the direction of the force exerted on the handle.

4. The frame according to claim 1, wherein the force detection assembly
comprises at least one strain gauge assembly.

5. The frame according to claim 1, wherein the force detection assembly
comprises at least one load cell.

6. The frame according to claim 1, wherein the control unit is configured
for generating a control signal for the pivot drive which is such that
the drive wheel is positioned in an initial condition with respect to the
bearing structure when no force is exerted on the handle.

7. The frame according to claim 1, wherein the pivotal angle for pivoting
the wheel support with respect to the bearing structure is bounded by at
least one bounding element.

8. The frame according to claim 1, wherein the pivot is oriented
substantially vertically.

9. The frame according to claim 1, wherein the wheel drive comprises at
least one hub motor which is provided substantially in a hub of the drive
wheel.

10. The frame according to claim 1, wherein the frame comprises several
wheel supports connected to the bearing structure in a manner pivotable
about a pivot, and comprises several drive wheels connected to the
respective wheel supports in a manner rotatable about a wheel central
axis.

11. The frame according to claim 10, wherein the several drive wheels are
mutually mechanically coupled.

12. The frame according to claim 1, wherein the frame also comprises at
least one support wheel connected to the bearing structure.

13. The frame according to claim 1, wherein the operating device is
designed as an operating device assembly which is connected to the frame
as a detachable unit.

14. The A frame according to claim 13, wherein the operating device
assembly also comprises an accumulator.

15. A mobile piece of furniture for moving persons, which piece of
furniture comprises a mobile frame according to claim 1.

16. A hoist for moving persons, which hoist comprises a mobile frame
according to claim 1.

17. A method for moving a person, comprising the steps of:providing a
mobile piece of furniture or providing a hoist, the mobile piece of
furniture or the hoist including a mobile frame according to claim
1;having the person to be moved sit down on the piece of furniture or in
the hoist; andexerting a force on the handle for moving the piece of
furniture or the hoist with a desired speed and direction.

18. The frame according to claim 2, wherein the force detection assembly
is configured for measuring an elastic deformation of the operating
handle and/or the bearing frame, which occurs under the influence of a
force exerted by a user on the handle and for converting this measured
deformation into signals which contain information about both the size of
the force and the direction of the force exerted on the handle.

19. The frame according to claim 2, wherein the force detection assembly
comprises at least one strain gauge assembly.

20. The frame according to claim 3, wherein the force detection assembly
comprises at least one strain gauge assembly.

Description:

FIELD

[0001]The invention relates to a mobile frame for moving less able-bodied
persons, in particular to be used in a hoist, a bed, a wheelchair.

BACKGROUND

[0002]A hoist provided with a pivotal drive wheel is known from
WO2004/069125 and U.S. Pat. No. 5,758,371. A hospital bed with a pivotal
drive wheel is known from WO2006059200A2, wherein different possibilities
are disclosed for effecting pivoting of the drive wheel.

[0003]The operation of the pivotal drive wheels takes place with the aid
of a generally known joystick. Such a control requires practice of the
user in the sense that the user has to accustom himself to the manner in
which the mobile frame reacts to a specific movement of the joystick.

SUMMARY

[0004]The invention has for an object to provide a mobile frame which is
provided with a drive, whose driving direction is controllable and which
has an intuitive control.

[0005]To that end, the invention provides a mobile frame, for instance for
moving less able-bodied persons, comprising: [0006]at least one base
structure; [0007]at least one drive wheel which is rotatable about a
wheel central axis; [0008]at least one wheel drive configured for driving
the drive wheel about the wheel central axis; [0009]at least one drive
wheel support which is connected to the bearing structure in a manner
pivotable about a pivot and with which the drive wheel is connected for
rotation about the wheel central axis; [0010]a pivot drive configured for
pivoting the wheel support about the pivot with respect to the bearing
structure; and [0011]operating means for operating the wheel drive and
for operating the pivot drive for moving the base frame, the operating
means comprising: [0012]a handle connected to the bearing structure;
[0013]a force detection assembly provided on the handle and/or on the
bearing structure, and configured for producing signals containing
information about both the size of the force and the direction of force
which is exerted on the handle; [0014]a control, of which an input is
connected to the force detection assembly, and of which a first output is
connected to the at least one wheel drive and of which a second output is
connected to the at least one pivot drive, the control being configured
for energizing the pivot drive for controlling the rotational position of
drive wheel support about the pivot depending on the direction of force,
while the control is configured for energizing the wheel drive depending
on the size of force exerted on the handle.

[0015]Such a mobile frame provides an intuitive control. Here, in one
embodiment, the handle is non-movably connected to the bearing structure.
Therefore, the care worker or user of the mobile frame pushes the
non-movable operating handle in the desired direction of movement. The
non-movable and hence direct coupling between the operating handle and
frame provides a secure sensation the user is acquainted to from
non-driven mobile frames for hoists, beds and the like. However, by the
force detection assembly, the force a user exerts on the handle is
detected and the drive wheel is pivoted by the control in a desired
direction and the drive wheel motor is driven at a speed which is related
to a force exerted on the handle. It is self-evident that this needs not
be a linear relation. However, in one embodiment, such a linear relation
is indeed a possibility. Through the use of the force detection means,
the drive means can already be activated by exerting a minimal force on
the operating means, which is further beneficial to the ease of use of
the frame according to the invention.

[0016]In one embodiment, the force detection assembly can be configured
for measuring an elastic deformation of the operating handle and/or the
bearing frame which occurs under the influence of a force exerted by a
user on the handle and for converting this measured deformation into
signals which contain information about the size of the force as well as
the direction of the force of the force exerted on the handle. The handle
may be manufactured from metal and the deformations which are measured as
a result of exertion of force can therefore be particularly small, such
that the user does not notice the handle slightly deforming.

[0017]In one embodiment, the force detection assembly can comprise at
least one strain gauge assembly. Such a strain gauge assembly can for
instance comprise a strain gauge for measuring deformation as a result of
a force in lateral direction and a strain gauge for measuring deformation
as a result of a force in longitudinal direction of the frame. The
signals of the two strain gauges together can thus contain information
about size of force and direction of force. With such a strain gauge
assembly, a simple and hence effective control of the frame can be
realized.

[0018]In an alternative embodiment, the force detection assembly can
comprise at least one load cell assembly. Such load cell assemblies are
commercially available at low cost price and are themselves often
provided with strain gauge assemblies.

[0019]In one embodiment, the control unit can be configured for generating
a control signal for the pivot drive which is such that the drive wheel
is positioned in an initial condition relative to the bearing structure
when no force is exerted on the handle. Thus, after operation of the
frame, the drive wheel will automatically return to the initial condition
in order to reach each successive condition as rapidly as possible during
a subsequent operation of the frame. In the initial condition, the drive
wheel can extend for instance in a plane which is parallel to a
longitudinal axis of the frame.

[0020]The pivotal angle for pivoting the wheel support with respect to the
bearing structure can be bounded by at least one bounding element. It can
thus be prevented that the wheel support is oriented back-to-front with
respect to the bearing structure, which could negatively influence the
propelling movement and hence the ease of use of the frame.

[0021]In one embodiment, the pivot is oriented substantially vertically.
Such vertical orientation enables simple pivoting. The pivot can be
staggered in horizontal direction with respect to the wheel axle.
However, it is also possible that the pivot central axis intersects the
wheel axle central axis. Here, it is preferred that the wheel central
axis is oriented substantially horizontally.

[0022]The wheel drive and the pivot drive can be of different nature, but
will generally each comprise an electric motor, so that both movements
can be made independently of each other in a relatively simple manner. In
an advantageous embodiment, the wheel drive is designed as a hub motor
which is provided substantially in a hub of the drive wheel. By means of
a hub motor, the drive of the drive wheel can be concealed in the drive
wheel relatively compactly and efficiently. A particularly advantageous
hub motor is formed by a so-called direct drive electric motor, with the
aid of which the hub is driven directly by the (electric) motor, without
the interposition of other mechanic components, which has as an advantage
that the direct drive electric motor will cause hardly any friction, if
at all, in case this electric motor is not active.

[0023]Although the use of only one single drive wheel suspended in a
single wheel support will, as a rule, already function in a particularly
satisfying manner, it is also conceivable that the frame comprises
several drive wheels. Here, the several drive wheels can be suspended in
a common wheel support or in different wheel supports.

[0024]It may then be advantageous when the several drive wheels are
mutually mechanically coupled, in order to guarantee a controlled and
relatively simple control of the frame. Apart from the use of at least
one separately driven propelling wheel and at least one separately driven
steering wheel, also, various variant embodiments are conceivable.

[0025]In addition to drive wheels, it is also conceivable that the frame
comprises one or more supporting wheels connected to the bearing
structure. As a rule, here, the passive supporting wheels are connected
in a freely pivotal manner, through the interposition of a wheel support,
to the bearing structure and can provide the frame with a desired
stability.

[0026]In one embodiment, the operating means can be designed as an
operating means assembly connected to the frame as a detachable unit.
This offers the advantage that a larger number of frames can be purchased
than the relatively expensive operating means. This may be of advantage
from a point of view of costs.

[0027]In a further elaboration, the operating means assembly can also
comprise an accumulator. When the operating means assembly is uncoupled
from the frame the operating means can be charged at a central location
while the piece of furniture or the hoist can be disposed at a location
suitable to the user.

[0028]The invention also relates to a mobile piece of furniture for moving
persons, which piece of furniture comprises a mobile frame according to
the invention. Here, the mobile piece of furniture can take the form of a
chair or bed.

[0029]The invention further relates to hoist for moving persons, which
were used comprises a frame according to the invention. Here, the frame
can be detachably connected to the hoist. The hoist then further be of
diverse nature and is preferably provided with a lifting arm connected to
the frame, which lifting arm is provided with optionally clamping
engaging means for engaging the person to be moved. By then moving the
lifting arm relative to the bearing structure, the person can be moved
from a first condition (lying, sitting or standing) to a second condition
(lying, sitting or standing). During driving of the mobile hoist, the
position of the person will usually not be changed.

[0030]The invention also provides a method for moving a person comprising:
[0031]providing a mobile piece of furniture according to claim 15 or
providing a hoist according to claim 16; [0032]having the person to be
moved sit down on the piece of furniture or in the hoist; and
[0033]exerting a force on the handle for moving the piece of furniture or
the hoist at a desired speed and in a desired direction.

[0034]As a rule, it is advantageous when a force is exerted on the
operating means, this force is detected and is converted by a control
unit into a control signal for controlling the driving means. By
electronically (digitally) driving the driving means, only a minimal
effort is required from a person for moving the frame at wish. In a
special preferred embodiment, a size of force exerted on the operating
means is converted into a control signal for rotating the at least one
drive wheel about the wheel central axis with respect to the at least one
wheel support and/or a direction of force exerted on the operating means
is converted into a control signal for rotating the at least one wheel
support with respect to the bearing structure. Such use of the exerted
force is beneficial to the steering sensitivity and hence the user
friendliness of the frame.

BRIEF DESCRIPTION OF THE DRAWING

[0035]FIG. 1 shows a perspective view to a mobile frame according to the
invention;

[0036]FIGS. 2a-2d show different schematic views to the control of the
frame according to FIG. 1;

[0037]FIG. 3 shows a hoist comprising a mobile frame according to the
invention;

[0038]FIG. 4 shows a mobile chair comprising a mobile frame according to
the invention; and

[0039]FIG. 5 shows a hospital bed with an exemplary embodiment of the
mobile frame.

DETAILED DESCRIPTION

[0040]FIG. 1 shows a perspective view to a mobile frame 1 according to the
invention. The mobile frame 1 is designed for transporting less
able-bodied persons and comprises a bearing structure 2 for a person to
be transported, wherein the bearing structure 2 can be provided with two
foot supports 3a, 3b, and two knee supports 4a, 4b on which or against
which, respectively, the person can bear. The frame 1 also comprises four
stabilizing castors 5a-5d connected to the bearing structure 2. In
addition, the frame 1 comprises a wheel support 6 connected to the
bearing structure 2 in a manner pivotable about a vertical axis of
rotation V, in which wheel support is provided a drive wheel 7, rotatable
about a horizontal axis of rotation H. The frame 1 comprises a pivot
drive which, in the exemplary embodiment, is designed as an electric
motor 8 for motorized rotation of the assembly of the wheel support 6 and
the drive wheel 7 suspended therein with respect to the vertical axis of
rotation V for steering the frame 1 sideways. In addition, the frame 1
comprises a wheel drive 9 which is designed in the exemplary embodiment
as an electric motor, more particularly as hub motor, in particular a
direct drive motor which is provided in a hub 10 of the drive wheel 7.
The wheel drive 9 is designed for rotating the drive wheel 7 in forward
or rearward direction and hence for propelling the frame 1. By means of
an operating handle 11, both drives 8, 9 can be selectively driven. Here,
the operating handle 11 is coupled to the bearing structure 2. The
coupling is non-movable. The operating handle 11 is provided with one or
more strain gauges (not represented) for detection of a size of force and
direction of force exerted on to the operating handle 11. By means of a
control unit 12, the forces exerted on the operating handle 11, detected
by means of the straining gauges can be converted into one or several
control signals for the purpose of controlling the pivot drive 8 and/or
the wheel drive 9.

[0041]The schematic operation of the mobile frame 1 shown in FIG. 1 is
shown in FIGS. 2a-2d. In FIG. 2a it is shown that in case a frontal force
F1 is exerted on the operating handle 11, the drive wheel 7 is in
line with the bearing structure 2, and the frame 1 will move in forward
direction D1. In case also a lateral force F2 is exerted on the
operating handle 11, the drive wheel 7 will rotate (under the influence
of the wheel support 6) with respect to the bearing structure 2, as a
result of which the frame 1 will be moved in a forward direction towards
the right D2 (FIG. 2b). As shown, the castors 5a-5d will follow the
orientation of the drive wheel 7 with respect to the bearing structure 2.
In case only a torsional force F3 is exerted on the operating handle
11, in one embodiment, the drive wheel 7 cannot react, so that the frame
1 can be manually rotated in a direction D3 (FIG. 2c). In case both
a lateral force F4,1 is exerted on the operating handle 11 and a
lateral force F4,2 is exerted in the same direction on the bearing
structure 2, the frame 1 will be moved under the influence of the drive
wheel 7 as such in the same direction D4 (FIG. 2d).

[0042]FIG. 3 shows a mobile frame 13 according to the invention comprising
a hoist 14 for moving less able-bodied persons. The hoist 14 further
comprises a bearing structure 15 provided with several supporting wheels
16 and one drive wheel 17, which drive wheel 17 can be driven by means of
an operating handle 18 for motorized movement of the frame 13 and hence
of the hoist 14. With regard to construction and operation, the frame 13
resembles the frame 1 shown in FIGS. 1-2d. The bearing structure also
comprises a foot platform 19 and knee supports 20 on which or against
which, respectively, a person to be moved can bear. The hoist 14 further
comprises an articulated lifting column 20 pivotally connected to the
bearing structure 15, to which column a clamping device 21 is connected
for clamping the person to be moved. With the aid of the telescopic
hoisting column 20, a clamped person can be moved following a natural
path from a seated position to a standing position and vice versa.

[0043]FIG. 4 shows a mobile frame 22 according to the invention comprising
a mobile chair 23 for efficiently moving less able-bodied persons. Here,
the chair 23 comprises a seat 24 to which two front wheel supports 25a,
25b are pivotally connected, while each wheel support 25a, 25b is
provided with a wheel 26a, 26b. One of the wheel supports 25a is coupled
to a first pivoting motor 27 for motorized pivoting of the wheel support
25a, and thus of the wheel 26a suspended therein. In the other front
wheel support 25b a drive wheel 26b is suspended, which drive wheel 26d
is provided with a hub motor 28 for propelling the chair 23. The two
front wheel supports 25a, 25b are coupled by means of a pivotal rod
mechanism 29 for guaranteeing a controlled moving of the chair 23. In
order to enhance the comfort for the person to be moved, the chair 23 is
provided with two foot supports. The two motors can be controlled by a
control which receives as input signals the signals from a force
detection assembly. The force detection assembly can for instance be
built-in in the two rods connected to the handles which, together, can
also be considered to be a handle. Optionally, the two motors 27, 28 can
also be selectively operated by means of a touch screen 31 connected to
the seat 24. The chair 24 further comprises two passive (rear) castors 32
connected to the seat 24 in a freely rotatable manner.

[0044]FIG. 5 shows an exemplary embodiment of a hospital bed 40 which is
provided with a mobile frame with a central, pivotal drive wheel 42 with
a wheel drive in the form of a hub motor 44 and provided with a pivot
drive 46 for pivoting the castor 42. At the corners of the bearing
structure 48 of the frame, pivotal supporting wheels 50 are mounted. At
the foot of the bed, an operating means assembly 52 connected to the bed
is arranged. The operating means assembly 52 may comprise a housing 54 in
which an accumulator and the control are included. The housing 54 can be
connected to a non-movable handle 56. On this handle 56 or the housing 54
connected therewith, the force detection assembly can be mounted. The
operating means assembly 52 can be connected by means of a cable 58 to
the hub motor 44 and the pivot drive 46. Optionally, on the operating
means assembly 52, operating buttons can be present for operating
functions of the operating means assembly 52. An advantage of such a
detachable operating means assembly is that a hospital needs not purchase
such a relatively expensive assembly for each bed. Another advantage is
that the accumulator can be charged at a central location.

[0045]It will be clear that the invention is not limited to the exemplary
embodiments represented here, but that within the framework of the
accompanying clams, numerous variants are possible which will be self
evident for the person skilled in this field of technology. A frame
according to the invention can for instance also be used for moving other
heavy loads, such as, for instance, a mobile X-ray machine or the like
where intuitive control is an advantage.